I would hope that the contributors to a core infrastructure project like gcc are able to do so because of their technical merits and not because they fit in wit

I would hope that the contributors to a core infrastructure project like gcc are able to do so because of their technical merits and not because they fit in with a set of arbitrary rules declared by a small, power-hungry group. As others have already pointed out, paradoxically, CoCs in OSS have done more net social harm than good. God forbid your project's top contributor use the word "guys" or "blacklist" else he'll be immediately ousted from the project.